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ct8775a manualCT8775C Heating-Cooling. Page 2 Enjoy the benefits of The Digital RoundTM Thermostat by Honeywell. WARPage 4: Step 3. Special Installations STEP 2. REMOVE OLD THERMOSTATIf you are replacing. Page 6 Mount Decorator Cover Plate (Optional) and Wallplate Directly to WallMount Decorator Cover Plate (Required) and Wallplate onto Electrical BoxPage 8: Step 7. Wire Wallplate Terminals STEP 7. WIRE WALLPLATE TERMINALSPage 9 Table 2. Terminal Designations on Old and New Thermostats.Set Fuel Switch (CT8775C Only)Page 11 Table 3. Heat Cycle Rate.Steam, Gravity 1. Page 12: Step 10. Set the System and fan Switches (CT8775C Only) STEP 10.Backlit. Page 14 Cooling System (CT8775C Only)Page 16 Wiring DiagramsHoneywell warrants this product to be free from defects in the workmanship or materials, under normal use. Page 19 19 69-1676—1Honeywell International Inc. Honeywell Limited-Honeywell Limitee. T est your heating and cooling systems to make sure they work properly. If using the decorator cover plate, pull the wires through the wiring hole on the decorator co ver plate. Mount Decorator Cover Plat e (Required) and Wallpl ate onto Electrical Box. Use DIP switch 3 to set the desired temperature indication. OPERATING THE THERMOSTAT NOTE: Batteries are not required because the tem peratu re setting is held permanently in memory. Can cause permane nt damage to compressor o r other equipment. At InstructionsManuals.com we have gathered together the manuals to make it easier for you to locate them. We take no responsibility for the validity of the information available in each manual nor do we have any affiliation with the brands nor their products. (Thermostats Honeywell). We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.http://ndesert.nazwa.pl/userfiles/elite-screen-manual.xml
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Note that email addresses and full names are not considered private information. Please mention this; Therefore, avoid filling in personal details. The manual is 0,44 mb in size. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive. Check your email Please enter your email address. Please check your inbox, and if you can’t find it, check your spam folder to make sure it didn't end up there. Please also check your spam folder. The temperature reading is easily seen from a distance. The temperature setting is held permanently in memory in the event of a power failure. Failure to follow these instructions can damage the product or cause a hazardous condition. Contact your local waste management authority for instructions regarding recycling and the proper disposal of an old control containing mercury in a sealed tube. If your system is not compatible, call Honeywell Customer Care, toll-free, 1-800-468-1502. Not compatible with Taco zone valves and 2- or 3-wire WhiteRodgers zone valves (No. 1311 and 1361). Save package of screws, instructions, and receipt. If the cover does not snap off when pulled firmly from the top or bottom, check for a screw or screws that may be used to lock on the cover. Do not disconnect wires. Wrap the wires separately using electrical tape. Place the wires where they will not interfere with the operation of the new thermostat. Continue with the installation at Step 4. If you have either one of these systems, return the product to the place of purchase. This thermostat is not compatible with these systems. For information about which thermostats will work with your system, call Honeywell Customer Care, at 1-800-468-1502. Continue with the installation at Step 4. If you purchased a CT8775A thermostat, return the product to the place of purchase.http://otticaleslunettes.com/admin/elite-screens-100-manual.xml The CT8775A thermostat is not compatible with this application. As you disconnect each wire, attach the enclosed labels with the old terminal designation. Wrap the wires around a pencil as shown to keep them from falling back into the wall. Separate the wallplate from the thermostat by placing your thumb on the top between the wallplate and the thermostat and pulling the thermostat away from the wallplate. See the illustration at the right. Position the decorator cover plate against the wall so that the UP indicator in the middle of the decorator cover plate is pointing up. Turn the wallplate until the wiring holes are aligned and the two screw holes on the left and right side of the wallplate line up with the screw holes on the decorator cover plate. You will be inserting the screws through these holes into the wall. Turn the dial to adjust the temperature setting. Large easy-to-read display. The temperature reading is easily seen from a distance. Backlit display. On-demand backlighting makes it easy to read the display in a dark room or hallway. No batteries required. The temperature setting is held permanently in memory in the event of a power failure. Page 3 STEP 1. PREPARE FOR INSTALLATION. Check Table 1, the compatibility chart, to make sure the thermostat is compatible with your system. If your system is not compatible, call Honeywell Customer Care, toll-free, 1-800-468-1502. Table 1. Compatibility Chart. Page 4 STEP 2. REMOVE OLD THERMOSTAT. Test your heating and cooling systems to make sure they work properly. Save package of screws, instructions, and receipt. Page 5 Replacing a thermostat that is connected to three wires on a warm air heating only system If you are replacing a thermostat that is connected to three wires on a warm air heating only system and could turn the fan on by setting the thermostat fan switch to ON, the CT8775C Thermostat will work with your system. Continue with the installation at Step 4. If you purchased a CT8775A thermostat, return the product to the place of purchase. The CT8775A thermostat is not compatible with this application. Page 6 Mount Decorator Cover Plate (Optional) and Wallplate Directly to Wall. If using the decorator cover plate, pull the wires through the wiring hole on the decorator cover plate. Position the WALL ANCHORS (2) decorator cover plate against the wall so that the UP DECORATOR COVER PLATE indicator in the middle of the decorator cover plate is pointing up. Page 7. Mount Decorator Cover Plate (Required) and Wallplate onto Electrical Box. R G ? Refer to the labels you placed on the wires when you removed the old thermostat (see illustration). ? Match the letter of your old thermostat wire with the corresponding terminal letter on your new thermostat. Refer to Table 2. Page 9 Table 2. Terminal Designations on Old and New Thermostats. Terminal on Old Thermostat Connect to Terminals on CT8775A Connect To Terminals on CT8775C Description R Rh (see Note 1) 4 V R R (see Note 2) Power Rc R (see Note 1) — Rc (see Note 2) Power for cooling W, W1, H W W Heat Y, Y1, M — Y Cooling G, F — G Fan O — O Changeover in cool. (Single stage heat pump only). B (see Note 3) — B (see Note 3) Changeover in heat. (Single stage heat pump only). Page 10 STEP 8. CUSTOMIZE THE THERMOSTAT Set Fuel Switch (CT8775C Only). This is the correct setting for gas or oil systems. If you have an electric heat system, or a heat pump, set the switch to E. The E setting allows the fan to turn on immediately with the heating system where the G terminal is connected. NOTE: The cooling cycle rate does not require adjustment and therefore cannot be changed. Page 12 STEP 10. SET THE SYSTEM AND FAN SWITCHES (CT8775C ONLY) System Switch (see Fig. 5) ? Heat: The thermostat controls your heating system. ? Off: Both the heating and cooling systems are off. ? Cool: The thermostat controls your cooling system. Fan Switch (see Fig. 5) ? Fan Auto: Normal setting for most homes. The fan only runs with the heating and cooling system. ? Fan On: The fan runs continuously. Use for improved air circulation. Page 13 STEP 11. OPERATING THE THERMOSTAT NOTE: Batteries are not required because the temperature setting is held permanently in memory. Backlit Display ? The backlight can be turned on by turning the dial, or pushing the backlight button (see Fig. 5). Display Temperature Setting. Turn the dial one click to display the temperature setting (see Fig. 6). A indicator points to Set when the temperature setting is displayed. ROOM SET M19489 Fig. 6. Temperature Setting Display. Page 14 Cooling System (CT8775C Only) CAUTION Equipment Damage Hazard. Can cause permanent damage to compressor or other equipment. Allow compressor to remain off for five minutes before restarting. See equipment manufacturer instructions. ? Slide the system switch to Cool and the Fan switch to Auto. ? Turn the dial counterclockwise to lower the temperature setting several degrees below the room temperature. Page 15 IF YOU HAVE A PROBLEM Table 5. Solution Guide. If. Display does not appear. Page 16 Wiring Diagrams O 2 R Rc R W 1 HEATING RELAY OR VALVE COIL 1 HEATING RELAY OR VALVE COIL 2 FACTORY INSTALLED JUMPER. M19450 O 2 Rc 1 B G Y W HEATING RELAY OR VALVE COIL COMPRESSOR CONTACTOR FAN RELAY 1 POWER SUPPLY.If, at any time during the warranty period, the product is defective or malfunctions, Honeywell shall repair or replace it (at Honeywells option) within a reasonable period of time. Using the online preview, you can quickly view the contents and go to the page where you will find the solution to your problem with Honeywell CT8775A. To start viewing the user manual Honeywell CT8775A on full screen, use the button Fullscreen. However, if you do not want to take up too much of your disk space, you can always download it in the future from ManualsBase. The option to print the manual has also been provided, and you can use it by clicking the link above - Print the manual. You do not have to print the entire manual Honeywell CT8775A but the selected pages only. paper. If you want to quickly view the content of pages found on the following pages of the manual, you can use them. Post your question here in this forum. We're committed to dealing with such abuse according to the laws in your country of residence. We'll get back to you only if we require additional details or have more information to share. Note that email addresses and full names are not considered private information. Please mention this; Therefore, avoid filling in personal details. Please enter your email address. Giv en klar og omfattende beskrivelse af problemet og dit sporgsmal. Jo flere oplysninger du giver om dit problem og dit sporgsmal, jo lettere er det for andre Honeywell CT8775A ejere at svare korrekt pa dit sporgsmal. Stil et sporgsmal Om Honeywell CT8775A Denne vejledning horer under kategorien Termostater og er blevet bedomt af 1 personer med et gennemsnit pa en 7.9. Denne manual er tilg?ngelig pa folgende sprog: Engelsk. Har du et sporgsmal om Honeywell CT8775A eller har du brug for hj?lp? Stil dit sporgsmal her Honeywell CT8775A specifikationer M?rke PDFmanualer.dk sikrer, at du hurtigt kan finde den manual, du leder efter. Vores database indeholder mere end 1 million PDF-manualer fra mere end 10.000 m?rker. Hver dag tilfojer vi de nyeste manualer, sa du altid kan finde det produkt, du leder efter. Det er meget simpelt: du skal bare indtaste m?rke og produkttype i sogefeltet og du kan straks se den manual du onsker, online og gratis. PDFmanualer. dk Hvis du forts?tter med at bruge dette site vil vi antage at du er indforstaet med det. L?s mere Ok. Operating the Thermostat Backlit Display Display Temperature Setting Adjust Temperature Setting Step 12.This manual answers many of the questions t hat can arise as you become familiar and comfortable with your Honeywell thermostat — the state of the art in home comfort controls. Read these instructions carefully. Failure to follow these instr uctions can damage the product or cause a hazar dous condition. MERCURY NOTICE If this thermostat is replacing a control that contains mercury in a sealed tube, do not place your old control in t he trash. Contact your local waste management authority for instructions regarding recycling and the proper disposal of an old control cont aining mercury in a sealed tube.If your system is not compatible, call Honeywell Customer Care, toll-free, 1-800-468-1502. T able 1. Compatibility Chart.Save package of screws, instructions, and receipt. ? Remove the cover from the old thermostat. If the cover does not snap off when pulled firmly from t he top or bottom, check for a screw or screws that may be used to lock on the co ver. ? Loosen the screw or screw s (if present) holding the th er mostat to the wallplate and lif t the thermostat away. NOTE: If none of the special installations apply to yo ur particular application, please skip to S tep 4. Replacing a thermostat that has wir es connected to C or C1 terminals If you are replacing a thermostat that has one or two wires connected to C or C1 terminals, do not allow them to touch, or you can damage the transformer. Wrap the wires separately using electrical tape. Continue with the installation at S tep 4. Replacing a thermostat that is connected to six or more wires If you are replacing a thermostat that is connected to si x or more wires (excluding wires connected to C or C1 terminals), you may have a multistage heat pump or other mu ltistage system. If you have ei ther one of these systems, return the product to the place of purchase. This thermostat is not compatible with these systems. For information about which thermostats will work with your syst em, call Honeywe ll Customer Care, at 1-800-468-1502. Continue with the installation at S tep 4. If you purchased a CT8775A thermo stat, return the product to the place of pur chase. Replacing a thermostat that is connected to three wires on a zoned hot water heating system If you are replacing a thermostat that is connected to three wires on a zo ned hot water heating system, the CT8775A,C thermostats will only work if an isolation relay is inst alled. Disconnect the wires from t he old thermostat. As you disconnect each wire, a ttach the enclosed labels with the old termi nal designation. Wrap the wires around a pencil as shown to keep them fr om falling back into the wall. STEP 5. SEPARATE WALLPLATE FROM THERMOSTAT. Remove cover from thermostat. Separate the wallplate from the thermostat by placing your thumb on the top between the wallplate and the thermostat and pulling the thermostat away from the wallplate. See the illustration at the right. STEP 6. MOUNT DECORATOR COVER PLATE AND THERMOSTAT WALLPLATE. The decorator cover plate and wallplate can be mounted dir ectly on the wall or onto an electrical box. ? T o mount directly to the wall, see Fig. 1. ? T o mount onto an electrical bo x, see Fig. 2. WIRES THROUGH WALL OPENING M5136 WALL PLATE THERMOSTAT COVER REMOVED M19492 If using the decorator cover plate, pull the wires through the wiring hole on the decorator co ver plate. Position the decorator cover plate against the wall so that the UP indicator in the middle of the decorator cover plate is pointing up. ? Position the wallplate. If using the decorator cover plate, pull the w ires through the wiring hole on the wallplate and place the wallplate over the decorator cover plate. Turn the wallplate until the wiring holes are aligned and the two screw holes on the left and right side of the wallplate line up with the screw holes on the decorator cover plate.Refer to T a ble 2. IMPORTANT Remove the factory-installed jumper connecting terminals R and Rc on the CT8775C Thermostat if wires will be con- nected to both of these terminals. ? For wiring diagrams, se e pp 16-17. ? Loosen the terminal screws. Slip each wire beneath its matching terminal. Wrap around and straight c onnections are both acceptable, (see illustration). T ighten the terminals. ? Plug the hole in the wall with insulation to help prevent drafts from adversely affecting thermostat operation.Connect O to O. T ape off B with electri- cal tape and do not use. 4. T ape off wire with electrical tape and do not use. T ermina l on Old Thermostat Connect to T erm inals on CT8775A Connect T o T erminals on CT8775C Description R Rh (see Note 1) 4 V RR (see Note 2) Power Rc R (see Note 1) —R c (see Note 2) Power for cooling W, W 1, H W W Heat Y, Y 1, M — Y Cooling G, F — G F a n O — O Changeover in cool. (Single stage heat pump only). B (see Note 3) —B (see Note 3) Changeover in heat. (Single stage heat pump only). C (see Note 4) X (see Note 4) B (see Note 3) Do not connect. Do not connect. T r ansformer common W 2, H 2 Do not continue installation. Call 1-800- 468-1502. Do not continue installation. Second stage heat. Y 2 Second stage cool. This is the correct setting for gas or oil syste ms. If you have an electric h eat system, or a heat pump, set the switch to E. T he E setting allows the fan to turn on immediately with the heating system where the G terminal is connected. Use DIP switches 1 and 2 to set the heat cycle rate. See T able 3. NOTE: The CT8775A,C Thermostats wi ll provide optimal temperature control if DIP switches 1 and 2 are set according to your partic- ular heating system. Fig. 3. Fuel switch. Fig. 4. DIP switch. M19497 FUEL SWITCH ON 1 2 3 M19567 BACK OF THERMOST AT DIP SWITCH Use DIP switch 3 to set the desired temperature indication.Fan Switch (see Fig. 5) ? Fan Auto: Normal setting for most homes. The f an only runs with the heating and cooling system. ? Fan On: The fan runs continuously. U se for improved air circulation. Fig. 5. CT8775 Thermostat (features and ope ration).Backlit Display ? The backlight can be turned on by turning the di al, or pushing the backlight button (see Fig. 5). Adjust Temperat ure Setting. T urn the dial clockwise to raise the temperature setting. Slide the system switch to Heat and the Fan switch to Auto (CT87 75C only). ? T urn the dial clockwise to raise the temperatur e setting several degrees above the room temperature. ? A flame will appear in the disp lay to indicate the thermost at has called for heat ing. The heati ng system should turn on. ? T urn the dial counterclockwise to lower the temperature setting below the room temperature. ? The flame will disappear from the di splay to indicate the thermostat has ended the call for heating. The heating system should turn off. Display Temperature Setting. T urn the dial one click to display the temperature setting (see Fig. 6). A indicator points to Set when the temperature setting is displayed. Fig. 6. T emperature Setting Display. ? If a change to the temperature setting is not made within five seconds, the mode will switch to the room temperature display (see Fig. 7). A indicator points to Room when the room temperature is displayed. Fig. 7. Room T emperature Display.Can cause permane nt damage to compressor o r other equipment. See equipment manufacturer instruction s. ? Slide the system switch to Cool and the Fan switch to Auto. ? T urn the dial counterclockwise to lower the temper at ure setting several degrees below the room tem perature. NOTE: If a call for cooling is made before the compressor has been off for five minutes, or if a power interruption occurs while the compressor is running, the thermostat will go into a five-minute delay to protect the com- pressor. The snowflake wi ll flash during this delay. ? After five minutes, the thermostat will display a solid snow flake to indicate the thermostat has called fo r cooling. The cooling system should turn on. ? T urn the dial clockwise to raise the te mperature setting above the room temperature. ? The snowflake will disappear from t he display to indicate the thermostat has ended the call for cooling. The cooling system should turn off. Fan (CT8775C Only). Slide the system switch to Off and the fan sw itch to On. The fan should run continuously. ? Slide the Fan switch to Auto. The fan shou ld turn off. W ait five minutes after seeing th e flame or snowflake and check the registers again. If there is no warm or cool air coming from the registers, refer to Heating does not come on or Cooling doe s not come on. If all of this has been checked, contact your lo cal heating and cooling contractor. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 FACTORY INSTALLED JUMPER. 2 W R Rc B O Y G PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 FACTORY INSTALLED JUMPER. 3 USE A JUMPER WIRE (NOT SUPPLIED) TO CONNECT W TO Y. 4 USE EITHER O OR B FOR HEAT PUMP CHANGEOVER. 3 2 W R Rc B O Y G 1 2 1 HEATING RELAY OR VALVE COIL COMPRESSOR CONTACTOR FAN RELAY M19454 1 POWER SUPPLY.If, at any time during the warranty per iod, the pr oduct is defective or malfunctions, Honeywell shall repair or replace it (at Honeywells option) within a reaso nable period of time. Honeywells sole responsibility shall be to rep air or replace the product within the terms stated above.This warranty gives you specific legal right s, and you may have other rights which vary from stat e to state. If you have any questions concer ning this warranty, please write Honeywell Customer Care, 1885 Douglas Dr. N., Golden V alley, MN 55422-3992. Please use the box above to search for any other information.Enjoy the benefits of the questions that contains mercury in a sealed tube, do not place your Honeywell thermostat - the state of the art in the trash. Turn the dial to use. The temperature reading is replacing a control that can damage the product.If this thermostat is easily seen from a distance. Failure to read display. COThank you! (Posted by isomody 6 years ago) Honeywell RTH4300B Answers Need A Manual For T8112 Thermostat Need a manual for T8112 Thermostat (Posted by julie31366 7 years ago) Honeywell T8112D Answers Why Cannt I Just Get Owners Manual Without All The Sales Stuff.still Need Manu JUST WANT MANUAL BUT YOUR SIGHT NEVER GETS ME TO RIGHT SPOT. JUST MORE SALES!!! (Posted by Applianceliquidators 8 years ago) Honeywell RTH4300B Answers It has new batteries. However, a full explanation of the MX4)U's product key is found at. Please use the box above to search for any other information.Thank you! (Posted by isomody 6 years ago) Honeywell RTH4300B Answers Need A Manual For T8112 Thermostat Need a manual for T8112 Thermostat (Posted by julie31366 7 years ago) Honeywell T8112D Answers Why Cannt I Just Get Owners Manual Without All The Sales Stuff.still Need Manu JUST WANT MANUAL BUT YOUR SIGHT NEVER GETS ME TO RIGHT SPOT. JUST MORE SALES!!! (Posted by Applianceliquidators 8 years ago) Honeywell RTH4300B Answers Please help, this machine, is given me to much of error. Remove the printer cover and the paper guide. Other top attributes are Round, mpn and Does Not Apply. Also round heat thermostat ct8775a is one of the best sellers in Honeywell, Honeywell Thermostat With Remote Sensor, Honeywell Thermostat Rth2300b and H in 2020. Our payment security system encrypts your information during transmission. We don’t share your credit card details with third-party sellers, and we don’t sell your information to others. Please try again.Please try again.Our technicians use the latest authorized manufacturer tools to help you troubleshoot issues. To access this option, go to Your Orders and choose Get product support.In order to navigate out of this carousel please use your heading shortcut key to navigate to the next or previous heading. Register a free business account Please try your search again later.To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyzes reviews to verify trustworthiness. Please try again later. TommyT 1.0 out of 5 stars However, heat runs continuously. As another reviewer stated mine does the same exact and that it shows 98 degrees room temp and set point 72 with heat running continuously to 85 degrees real temperature indicated by my thermal gun. Also display doesn’t show at all except briefly. The display shouldn’t disappear from this model. I’m one and done and bought another Honeywell model for much less and made in USA instead of this China model.Please understand that I consider it to be an excellent thermostat in the proper circumstance; it's just that the heating system in the house is not that. That system is an oil-fired boiler which provides both hydronic baseboard heating through five heating zones and domestic hot water through a tankless hot-water coil in the boiler. Each heating zone is controlled by a thermostat connected to a 24 volt relay coil in a Honeywell relay switch which, in turn, controls the circulator pump for that zone. In order to insure optimum recovery when the boiler temperature drops low enough to fire the boiler, the boiler control circuit is wired to remove all power from the hydronic heating zones when the boiler fires. That way, the heating load on the boiler is suspended while the boiler is reheating. As I understand it, this arrangement allows the boiler to recover with a smaller oil spray orifice and, therefore, less wasted heat (fuel) going out the exhaust stack. Therein lies the source of the problem in my particular installation. When the boiler control circuit removes all power from the five zone relay switches, the 24 volt control circuits have no power -- no 24 volts to maintain the circuit in the thermostat. When the boiler has recovered to its set temperature and stops firing, the boiler control circuit reapplies power to the hydronic zones and power is restored to the thermostat. However, having likely lost its setting due to the temporary power loss, the thermostat usually has to be reset. What I've described is not an issue during AC season as the domestic hot-water coil has no effect in this matter. Fortunately, only one of these thermostats was installed because I wanted to ensure its compatibility with the heating system before I spent the money for several units. Please note that if you are considering this thermostat for a system that does NOT periodically suspend power to the control circuit that feeds the required 24 volts to the thermostat, there is no reason that I know of that it would provide anything but excellent service. So, how to rate this thermostat. For my purposes, it's one star because I can't give it zero. For someone else's system which maintains control circuit power (I would think that would mean anything but a hydronic system such as mine), I would still recommend this thermostat. It's a classic looking unit with, as a year's experience has proven, a very accurate ambient temperature indicator and a very accurate control circuit. For a different system, then -- five stars. Taking the average of the two scoring scenarios -- three stars!After two weeks it started behaving erratically, losing its set point. I came home one day and the temperature was in the 80's whereas the set point was mid 60's. The heat had obviously been on for quite a while. When I rotated the housing to access the set point it would first not respond at all (blank) and, after a number of tries, show the correct set point for a moment before reverting to a temperature in the high 80's. Even after I opened the windows to lower the room temperature it still responded the same. Therefore, I assume the thermostat was showing a bogus set point in the 80's rather than reading the room temperature. I had to pull the thermostat from the wall to shut off the heat. I see from the reviews that a number of users had a similar problem. I probably should not have taken the chance to buy it but it was exactly what I wanted for a heat only system and some customers did have good luck with it. I called Honeywell and they were useless, trying to come up with all kinds of reasons to put the blame elsewhere than where it belonged. Fortunately I had bought it from Amazon and had no trouble returning it. That kind of service is why I buy so much from them. However it is sad that there are too many poor products on the market and that a company like Honeywell, which used to have a great reputation, will not stand behind their product. I ended up putting up the old thermostat which I had replaced because it wasn't very attractive and it works fine. I guess I am stuck with it. I do have to admit that it was also a Honeywell, apparently a model with better quality control.HVAC systems must be absolutely reliable and run for decades without fault. Honeywell has been around long enough to know and appreciate this.I wont purchase another thermostat on Amazon or anywhere online. Too much risk.It installed fairly easily but right away I had a few problems. The main problem was that this thermostat constantly read way higher than the rooms actual ambient temperature. The zone controls can cause a voltage drop which for whatever reason makes this thermostat call for heat nonstop. The solution is to install the included resistor but the instructions don’t really help if you don’t have the exact components that they use as examples.But it died, won't show the ambient temperature or anything, just a dead thermostat!Sorry, we failed to record your vote. Please try again It is far more accurate than the previous mercury version.Sorry, we failed to record your vote.